It's a common phrase used to express:
* Affection: "Mi vida" can be used as a term of endearment for a loved one, similar to "my love" or "my darling."
* Possession: It can also be used to emphasize a strong connection to something or someone, like "my life's work" or "the love of my life."
* Importance: It can be used to highlight the significance of something in one's life, like "My life's goal is to..."
The exact meaning of "mi vita" will depend on the context in which it is used.